Towing and towed vehicles are used frequently to transport various equipment from one location to another. In order to prevent excessive brake wear on the towing vehicle, the towed vehicle should be provided with brakes responsive to the slowing and stopping action of the towing vehicle. The brakes for the towed vehicle may be, for example, directly connected to the braking system of the towing vehicle. However, this type of braking system is relatively expensive to purchase or install so a surge brake system may be used to reduce costs.
Surge brake systems for towed vehicles are well known in the art and are used to automatically apply the brakes of the towed vehicle. A typical surge brake system is connected to the hitch and has a hydraulic cylinder which operates in response to the relative telescopic movement between two members. Relative telescopic movement of the two members occurs during slowing, stopping, or backing of a towing vehicle when the towed vehicle advances toward the towing vehicle. Although braking is necessary on the towed vehicle when the towing vehicle slows or stops, it is detrimental to have the brakes applied to the towed vehicle during backing of the towing vehicle. The application of the brakes of the towed vehicle during backing may damage the towing vehicle or lead to premature wear and possible failure of the brakes on the towed vehicle. In addition, when the towing vehicle is backing up on an inclined surface the application of the brakes of the towed vehicle may completely prevent the backing maneuver.
It is known that a valve can be used to disable the surge brake during backing of the towing vehicle and prevent the application of the brakes on the towed vehicle. However, the valve is closed manually by an operator. If the valve is not reopened after backing the towing vehicle, due to human error, the towed vehicle no longer has any braking capabilities. Without the brakes on the towed vehicle, excessive brake wear on the towing vehicle as mentioned above is again encountered.
The present invention is directed to overcoming one or more of the problems as set forth above.